Subscribe to Spaceflight Now Plus for access to our extensive video collections!How do I sign up?Video archiveSTS-119: The programsIn advance of shuttle Discovery's STS-119 mission to the station, managers from both programs discuss the flight.PlaySTS-119: The missionA detailed preview of Discovery's mission to deliver and activate the space station's final power truss is provided in this briefing.PlaySTS-119: SpacewalksFour spacewalks are planned during Discovery's STS-119 mission to the station.PlaySTS-119: The CrewThe Discovery astronauts, led by commander Lee Archambault, meet the press in the traditional pre-flight news conference.PlayBecome a subscriberMore video

Welcome home, Discovery!
BY WILLIAM HARWOODSTORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSIONPosted: March 28, 2009;Updated after news conferences

The shuttle Discovery glided to a windy touchdown at the Kennedy Space Center today, wrapping up a challenging three-spacewalk mission that left the international space station with a new set of solar arrays and a repaired water recycling system.

Credit: NASA-KSC

Running one orbit late because of high winds and low clouds, commander Lee Archambault and pilot Dominic "Tony" Antonelli guided the orbiter through a partly cloudy sky to a tire-smoking touchdown on runway 15 at 3:13:17 p.m.

"Houston copies, wheels stopped," replied George Zamka from Houston. "Welcome home, Discovery, after a great mission to bring the international space station to full power. ... To the entire crew of STS-119, great job everybody."

"Thank you very much, it's good to be back home," Archambault said.

Mission duration was 12 days 19 hours 29 minutes and 33 seconds, covering 5.3 million miles and 202 complete orbits since blastoff March 15 from nearby pad 39A.

Archambault, Antonelli, flight engineer Steven Swanson, John Phillips, Joseph Acaba and Richard Arnold doffed their pressure suits and gave Discovery a quick runway inspection before heading back to crew quarters.

"We had a very successful mission, I'm very proud we were able to bring up the S6 truss, the final power segment for the international space station, and we're very, very happy we were able to bring Discovery right back here to the Kennedy Space Center in Florida," Archambault said on the runway.

Said Launch Director Mike Leinbach, "the vehicle performed great, it looks good on the runway, very few dings to the tiles, it looked really, really good."

Returning space station flight engineer Sandra Magnus made the trip back to Earth resting on her back in a recumbent seat set up on the shuttle's lower deck to ease her transition back to gravity after four months in weightlessness. She did not join her crewmates on the runway, but Archambault said she came through entry "doing extremely well for someone who's been in space for four months. She was in very good spirits."

Magnus was replaced aboard the station by Japanese astronaut Koichi Wakata, who took off aboard Discovery and who remained behind when the shuttle departed Wednesday.

During re-entry, Discovery's crew participated in a final experiment. A heat-shield tile on the underside of the ship's left wing was modified to affect the flow of air across the belly of the orbiter during its high-speed descent to learn more about the physics of hypersonic flight. The data are expected to pay dividends when it comes to designing heat shields for future spacecraft.

LeRoy Cain, deputy manager of the shuttle program at the Johnson Space Center in Houston, said an aircraft flying below Discovery was able to photograph the ship's plume with an infrared camera as Discovery descended toward Florida. That imagery will be combined with temperature measurements from sensors on the shuttle to help engineers map turbulent air flow and its roll in re-entry heating.

"All indications are we were able to capture some good data," Cain said. "It's the only vehicle that flies like this in a hypersonic regime where we're able to capture this kind of aerodynamic data. So we're real excited to get this test data."

As Discovery's crew prepared for re-entry today, station commander Mike Fincke, Yury Lonchakov and Wakata, orbiting at a slightly higher altitude more than 1,000 miles behind the shuttle, welcomed two more crew members - and one guest - aboard the international outpost.

Expedition 19 commander Gennady Padalka, NASA flight engineer Michael Barratt and space tourist Charles Simonyi, making his second paid trip to the station, docked at the Zvezda command module's aft port at 9:05 a.m. After leak checks, they floated into the station around 12:36 p.m.

Padalka and physician-astronaut Barratt are replacing Expedition 18 commander Fincke and Lonchakov, who were launched to the outpost last October. After a 10-day handover, Fincke, Lonchakov and Simonyi will return to Earth aboard the Soyuz TMA-13 spacecraft on April 7.

If all goes well, three more crew members - cosmonaut Roman Romanenko, European Space Agency astronaut Frank De Winne and Canadian Space Agency astronaut Robert Thirsk - will ride another Soyuz to the lab complex in late May, boosting the full-time crew to six for the first time.

The Discovery astronauts paved the way to the latest space station milestone by installing a fourth and final set of solar arrays and delivering a replacement centrifuge for the lab's urine recycling system.

The new arrays will double the amount of power available for scientific research, from 15 kilowatts to 30 kilowatts, and the water recycling system will provide water for drinking and personal hygiene after the shuttle is retired in 2010.

A team of engineers was standing by in Florida to remove water samples from Discovery that will be analyzed to determine purity. If all goes well, station crews could be cleared to begin using recycled water within a month or so.

Discovery also brought back frozen blood, urine and other biological samples collected over the past few months as part of on-going space medicine research aboard the station.

With Discovery safely back on the ground in Florida, NASA plans to move the shuttle Atlantis to pad 39A Tuesday to prepare the ship for launch May 12 on a long-awaited mission to service the Hubble Space Telescope.

Because Hubble is in a different orbit from the space station, the servicing crew cannot seek safe haven aboard the outpost if any major problems threaten a safe re-entry. From the beginning, NASA managers have planned to have a second shuttle - Endeavour, in this case - ready for launch on a quick-response rescue mission if necessary.

NASA managers looked into the possibility of using the same launch pad for Atlantis and Endeavour, but Gerstenmaier said today Endeavour would be mounted on pad 39B while Atlantis is processed on nearby 39A. Pad 39B had been booked for a test flight of NASA's new Ares rocket, but that launch is being delayed and Endeavour will use the pad instead to improve processing efficiencies.

"We've talked to the teams, we've decided to use two pads for the HST flight," said Bill Gerstenmaier, director of space operations at NASA headquarters.

After Atlantis takes off, assuming a rescue flight is not needed, Endeavour will be moved over to pad 39A for work to prepare the ship for blastoff in June on another space station mission.

"As we look forward a little bit to the future, we've got to start thinking now about how we're going to really utilize space station," Gerstenmaier said. "I would just ask us all to stop for a moment and reflect on what's happening in space. ... This is a very special time in space flight and we need to make sure we get the absolute most out of it."

Antonelli clearly got the most out of his first space mission. Talking to reporters after landing, he summed up his experience saying "this whole living in 1-G thing is for the birds. Zero G, I think, is the way to go. It's a blast!"